I do both, TIG brazing (with silicone bronze rod only, I wish I could get some of that aluminium bronze here...) and oxy-fuel brazing. The difference is indeed like night and day.I have MIG brazed for over 20 years. Brass just acts differently than steel, it's weird.
I have never had it suck in a joint, can burn away the steel if too hot, It never gets the
"fluidity"(?) that happens with oxyfuel brazing.
I tried TIG brazing once and couldn't get close to making it work.
However, both methods have their strengths and weaknesses. TIG doesn't wet at at all for me. When it melts it almost doesn't flow. It seems a lot more viscous than steel. But it can be pushed with a rod. It is fairly easy to TIG braze on top of a corner, or near a slope where with oxy-fuel braze would just run down. In general I use TIG for 99% of stuff. Only when large surfaces are to be joined and one needs to have the joint wet in between I'd use oxy-fuel.
Also, when I'm TIG brazing cast iron I use AC TIG. On clean steel DC.